Psms Grade 6 Earthquakes/volcanoes

Front 1

stress

Back 1

a force that acts on rock to change its shape or volume

Front 2

tension

Back 2

stress that stretches rock so that it becomes thinner in the middle

Front 3

compression

Back 3

stress that squeezes rock until it folds or breaks

Front 4

shearing

Back 4

stress that pushes masses of rock in opposite directions, in a sideways movement

Front 5

earthquake

Back 5

the shaking and trembling that results from the movement of rock beneath Earth's surface

Front 6

focus

Back 6

the area beneath Earth's surface where rock that is under stress breaks, triggering an earthquake

Front 7

epicenter

Back 7

the point on the surface directly above the focus

Front 8

seismic waves

Back 8

vibrations that travel through Earth carrying the energy released during an earthquake

Front 9

Primary Waves (P Waves)

Back 9

seismic waves that compress and expand the ground like an accordian

Front 10

Secondary Waves (S waves)

Back 10

seismic waves that vibrate from side to side as well as up and down

Front 11

Surface Waves

Back 11

seismic waves that move more slowly but can produce sever ground movements

Front 12

volcano

Back 12

a weak spot in the crust where molten material, magma comes to the surface

Front 13

magma

Back 13

a molten mixture of rock-forming substances, gases, and water from the mantle

Front 14

lava

Back 14

magma that has reached Earth's surface

Front 15

Ring of Fire

Back 15

a major belt of volcanoes that rims the Pacific Ocean

Front 16

hot spot

Back 16

an area where material from deep within the mantle rises and then melts, forming magma